The versatile element, iron, facilitates essential biological functions, provides colors for the artist’s palette, and is abundant on Earth as well as on other planets.
Although we think of our bodies as containing mostly water and organic/carbon-based molecules, nature selectively uses a few metallic elements to perform specific functions.
Iron is the center of the hemes in hemoglobin, which are the molecules in red blood cells that pick up oxygen from the lungs and transfer the oxygen throughout the body. It is also important to healthy brain functioning and several other enzyme processes in the body. Thus, it should come as no surprise that iron also features prominently on the list of ingredients in most multi-vitamins.
One of the seven metals that alchemists attempted to convert into gold, iron is also depicted metaphorically by the Roman god of war, known as Mars, since weapons such as swords were often made out of iron. Indeed, that association is so strong that iron oxide compounds used to produce shades of red, orange, and brown in painting are still referred to as “Mars pigments.”
The reaction of iron oxide and aluminum powder is known as the thermite reaction, which is a popular chemical demonstration and has applications in welding and in the purification of other metal ores.
Iron is also important in planetary studies. Because iron is so easily oxidized to rust, some of the only elemental iron found on Earth is contained in meteorites. Iron ranks sixth in elemental abundance on Earth, and iron oxide is the source of the color of the red planet, Mars.